Rotary tube furnaces and the reactor vessels are typically used to process granular powder at high temperature. The tube is rotated and serves two purposes. First, the rotation overcomes the grain's angle of repose and thereby produces gravity flow through the tube. And, second, rotation facilitates gas-to-grain contact by the overturning action it provides. When process gases are used in conjunction with rotary tube reactors, the tube is usually modified with apertures to control gas flow and grain movement.
As is shown in Goldblatt, batch reactor systems are known and have been found to successfully restrict ambient atmosphere from certain regions within a reactor tube. But, these systems work as a batch system wherein a granular product G is loaded into a reaction zone RZ and remains in this reaction zone until a desired reaction is completed. Then, the granular product is removed from the reaction zone. As a result, product is intermittent and production rates are dependent on the size of the reaction zone and the time to complete the reaction.
Shown in FIGS. 1-3 is a batch reactor system BRT having a reactor tube T and reaction zone RZ that is generally central within tube T. In operation a grain G is introduced into tube T by way of an upper opening UO and enters an upper region UR. System BRT is oriented at a downward angle and rotates about a tube axis TA a first rotational direction such that grain G moves toward a first disk FD and enters reaction zone RZ by way of a plurality of feed openings FO and feed flaps FF in first disk FD that are provided along the circumference of disk FD. Feed Flaps FF are oriented in such a way that they scoop or force the granular material G into the reaction zone when tube T is rotated in the first rotational direction.
Tube T further includes a second disk SD spaced from first disk FD which together define reaction zone RZ. However, while second disk SD also includes a plurality of openings along its circumference, these opening are exit openings and have exit flaps EF that are oriented such that rotation about tube axis TA in the first direction does not produce the “scooping” of the material G and, therefore, does not produce an exit flow out of the reaction zone. Thus, when rotation is in the first rotational direction, the reaction zone will be loaded with granular material G and will form a grain bed GB. Granular material continues to be loaded into the reaction zone until a desired grain bed is achieved and the tube then continues to rotate in the first rotational direction for a designated time for the desired reaction. Once the desired processing/reacting time is achieved, rotation is reversed such that exit flaps EF can “scoop” the granular material of grain bed GB out of the reaction zone into lower region LR. The grains then exit tube T by way of Lower Openings LO.
Feed openings FO, feed flaps FF, exit openings EO and exit flaps EF are fashioned from radial slits separated by ninety degrees from one another. The region of the disk adjacent to the slit is bent out of the plane of disks to create a triangularly shaped flap and the orientation of the flap depends on whether the flap is a feeding flap or an exiting flap to produce the desired “scooping” action depending on the direction of rotation. The arcs of the flaps are welded to an inside surface IS of a tube T of system BRT as are the circumferences of the disks.
Once a desired grain bed is created in reaction zone RZ, a process gas PG is introduced into reaction zone RZ by way of a small axial hole AH in second disk SD that is just large enough to accept a gas injector tube (not shown). The small amount of open area in the disk produces the desired restriction in gas flow along with a negative pressure condition at the upper end of the tube. The application of the process gas can continue for the duration of processing time for the batch process.
Although satisfactory in many respects, a need exists for an improved interior configuration for a tubular vessel, and for a component to be incorporated therein, that governs and more accurately controls flow of granular or particulate material through a rotary tube vessel and/or allows continuous processing.